Fuel injection nozzle



March 14, 1961 1 GARDAY FUEL INJECTION NozzLE Filed Sept. 30, 1955 IN VEN TOR. LOUS J. GARDAY MMM ATTHNEYS 2,914,881 Y FUELINJECHON NozzL-El Imis J. Gamay, Sidney, N.Y., miglior in 'merenda Corporation, a` corporationrof Delaware rneavseps so,- 1 9 ss, Sgam; 531,651 A @Lani-sasl" This invention relates to fuel injectionapparatus for solid fuel injection engines and more particularlyto inject-ion nozzles yand spray tips therefor. Y

One of the objects of the present invention is to provide a novelly constructed nozzle for useV in injecting liquid -fuels into the combustion chambers of internal combustion engines and the like in a more desirable Patented Mar. 14, 1961 internally threaded at the vopposite end to receive a nut 12. A valveguide or adaptor 14 abuts the lower end of body and has a central bore coaxial with the bore through said body.

A valve 15 is slidable yin the bore of adaptor 14 and has a reduced cone-shaped portion at one end which engages a valve seat 16 in a reduced bore portion of the adaptor. A-,chamber 17 surrounds the lower or reduced yend, of valvej15 and is connected with a suitable supply of liquid fuel through a plurality of passages. 18 and a groove 19 in adaptor 14 and apassage A20 in body l1l). The upward or opening movement of Hvalve 15- in response to pressure applied to fuel,A in chamber 17 is preferably limited ,by body 10 which is engg'eable by'an annular shoulder o n the valve.

A reduced upper end portionV 21 of valve 15 'extends into the b ore of body 10 for operative engagement with a pressure rod or spindle 22. A Vspring 23 interposed between said spindle and nut 12 yieldably maintains valve 15 -on its seat 16. Shims 24 may be provided within nut 12 for adjusting the tension of spring 23.

One form of novel spray tip assembly contemplated by the invention is supported by and projects from the lower end of nut 11. In the illustrated embodiment, this assembly comprises only two parts, one of which is a simply constructed casing 25 having an external flange with less penetration into the compressed gases in the chamber than occurs with'nozzles. now in common use.

A further object is to provide novel means in a fuel injection nozzle for obtaining better atomizationv of the liquid fuel than is possible with known types of nozzles', .such as the so-called pintle type nozzles, that discharge the fuel into the chamber in the form of a wide coneshaped spray.

A still further object is to provide a novel spray tip y unit for a fuel injection nozzle which is readily separable from the nozzle valve and holder assembly and hence, easily replaceable, thereby reducing the over-all cost 0f installing and maintaining vfuel injection equipment of an engine or the like.

Still another object is to provide fuel injector spray tip assembly which is novelly constructed in such a manner ,that the same will produce aturbulent spray discharge, either coaxially with o`r at a desirable angle to the longitudinal axis of the nozzle holder with substantially equal effectiveness and etiiciency, thereby permitting more "convenient installation in a variety of engines.

The above and further objects and novel features of the present invention will more fully appear'from the following detail description when the same is read in connection with the accompanying drawings. It is to be expressely understood, however, that the drawings are for the purpose of illustration only and are not'intended as a definition of the limits of the invention.

In the drawings, wherein like reference characters refer to like parts throughout the several views,

'Fig. 1 is a vertical sectional view of one form of fuel injection nozzle embodying the invention;

Fig. 2 is an enlarged sectional gview of the spray tip embodied in the nozzle of Fig. 1; and,

' 'Fig Y3 is a detail diagrammatic view showing a preferred form of spiral groove for the spray tip core.

The single embodiment of the invention illustrated, by way ofexample, in the accompanying drawing is shown in combination with a well known type of fuel injection no zzle valve and holder assembly comprising a nozzle holder body 10 which is externally threaded at one end 'to 'receive a tubular tip holder or sleeve nut 11 and 26 that is wedged between valve adaptor v14 and ari internal shoulder in sleeve nut 11. The lcweror outer end of casing 25 is` preferably tapered or cone-shaped, and the interior of the casing is hollowed out to profvide a cylindrical bore 27 and a cone-shaped bore portion 28 in the conical end thereof. An outlet of spray orifice 29. is cut through the end wall of the casing in a desired relation to the longitudinal axis of'the casing and complete nozzle assembly. Orifice 29 is preferably, though not necessarily, cylindrical, and the internal Wall thereof at the outermost end should make a sharp .angle or edge with the outer end surface of casing 25. It is desirable to locate the inner end of orifice 29 near Vthe apexfof the internal conical wall surface 28. As shown, the axis of yorifice 29 makes an angle of about 40 degrees with the axis of the casing, but these axes may make any other desired angle with each other, depending upon the circumstances of the installation on an engine orthe like.

The other part of the spray jtip comprehended. and

' illustrated is a novelly constructed insert or coreV 30 ;se

cured within casing 25. A cylindrical portion 3l of the core has a tight, press tit in cylindrical bore portion?? and preferably terminates flush with the end surface of casing 25 which engages the discharge end of valve adaptor 14. lf desired, the casing and the insert or core may be spot or heliarc Welded .or otherwisesuitably secured to one another. Intermediate itsv ends, the insert hasv a reduced or undercut portion 32 which provides an annular ow chamber 33. The remaining en d por,v tion of the'insert has one or more, 'preferably Ytwo :or three, spiral grooves 34 cut therein. The full diameter of insert 30 and hence, grooves 34, preferably Aterminate in or nearthe plane of the intersection of thewallsv of cylindrical bore 27 with conical bore portion l28, and if desired, the insert may have a reduced tip 35 which is illustrated as being conical. Betweenfithe end of core 30 and casing '25, there is thus provided a cone-like chamber 36 which communicates with acomv-bustion chamber or the like through orifice 29 and may be suitably referred :to as a turbulence'chamber. The transverse sectional shape of grooves 34 is preferabljI that which is illustrated in Fig. 3,` and the radialdepth of the grooves is preferably slightlygreaterlthan the insert. In the latter case, eaclrof the. grooves should run out in the surface of 'the undercut portion, as illustrated vat 37, andthe lands at the discharge ends of the said grooves at the end adjacent chamber 36 should be sharp toinsure a turbulent swirling motion of the fuel 'discharg'e'from'the grooves intogthe turbulence chamber. Insert "30 'hasa vcentral fuel `Vpassage 38` :extending into the 'undercut' portion 32 thereof'and Connected by.one or more radial ports 39 with annular chambera'33. Fuel which passes -valve 15, 16 thusliows'throughY passages 38`and 39, annular'chamberV 33, Y'spiral grooves i34, turbulence chamber 3 6, and 4outlet orifice Z9'into a combustion chamber. As mentioned above, Va turbulent,

abreast chamber, ysaid shell-having a discharge yorifice in the end swirling Vmotion is imparted to the 'fuel' as -it passes through grooves l34 into thelargestj-diameter'end of :.tur#

bulence chamber 36. As the lswirling fuel approaches orifce29lalong the converging walls Aof chamber 36, the radius of the swirling path of the fuel vis gradually diminished. It 'is believed that the swirling motion conn The type of spray thus produced has 'comparatively Y Y short penetration and is very desirable in certain types Yof combustion chambers. The extent or degree of penetration, as well as other characteristics ofthe Vejected fuel and 'its pattern, may be controlled by varying the velocity of the fuel liow and hence, the turbulence thereof, by varying the directional angle or pitch of the spiral grooves V'34, by varying the diameter of the turbulence chamber and the taper of the walls, thereof, `or by varying the wallV thickness at the end of casingiZS and hence, the

v axial length of orifice 29. Everything else being equal, v

" ofsaid discharge orifice.

a large angle between the axis of the spray tip assembly .andthe axis of oriiice 29 or a relatively large'diameter ,swirl chamber will produce better dispersion, higher line fpressures and less penetration. The turbulence Velocity may be controlled by varying the ow areas through the spiral grooves in relation to the llow area of the outlet orifice 29. 'The total ow area through the spiral grooves 34 should be considerably in excess of the 'ow area through orifice 29 in order to insure unrestricted ow through Ythe spiral grooves. It has been found ing said chambers, said shell'having an outlet orifice in 'that the uniformity of dispersion and atomization is in- ;uenced by ,the number A,of spiral grooves, i greater uni- @formity being attained with a greater number of grooves.

. Ihere is thus provided a novelvspray oidischargetip assembly for a fuel injection nozzle of the type usedjin 4solidfuel injection engines .or in knozzles for spraying other types ofliquidsfor a variety of purposes. Y

V.'1`heconstruction contemplated is simple, comprising aonly two relativelysimple parts which maybe readily and .quickly assembled. vThe Ydevice is also readily re- ,placeable ina complete nozzle assembly,.thereby renderingit keasy to obtainrnostV efficient operation at minimum cost.

`Although only a .single embodiment of the invention .has .been illustrated inthe accompanying Vdrawings and described in detailin the foregoing specication, it is to ,be expressly understood that the invention is `not limited thereto., For example, Vthe outer wall vofthe turbulence chamber maybe arcuately concave or partially concave Iand partially conical as distinguished from cone-like, as illustrated in the drawing. The same is true of the tip j Y35, :the lsurface vot which-may be arcuately convex or .somewhat spherical. Also,'the spiral grooves or chan- ;nels'by means of which the liquid is Ydischarged with a Aswirling ;motion into the turbulence chamber .may be Elorm'edbyinternal threads in the boreor counterborerof sshell 25,;and 'fuelmay beisupplied to annularflow cham her133through1channels at the periphery rot lcore piece 1:30 Ainstead of through the central and radial passages illustrated. Variousother changes may Ialso be made, .particularlyin the design and arrangementvof Vpartsillusmated, without departinglfromlhe spiritandiscope ofthe thereof communicating-with :the turbulencegchamber adjacent the` longitudinal axis -thereof, ztheaxis of said ori* tice extending at an angle Vto the longitudinal axis of said counterbore and `at approximately Jvaaight angle to the surface of the wall of said turbulence chamber at the inner end of said orifice..

2. Apparatus as defined in claim l wherein the end wall-ofthefcounterbore forming av wall of -saidjturbulence chamber tapers to the longitudinal axis of the counter bore and the discharge end of said spiral passage'is rat the periphery of the largest diameter end of 1said -taperying '-wall of the turbulence chamber. j

V3. Apparatus as defined in claim 2 wherein said core means `has acentral tip portion forming a wall -of said turbulence chamber, the surface of Awhich tip portion converges to said axis in thesame-direction as the tapering end wall ofthe-counterbore, the intersection of said Aaxis 4and said end Awall being in spaced relation to Vthe free end of said tip portion.

4. YApparatus as dened lin claim 3 wherein lthe end wall of the counterbore and the surface of 'saidtip por'- tion diverge with vrespect to -each other 'inl the direction bore, the end wall of Vthe bore forming said chamber'` converging toward the longitudinal axis of the bore lat an acute angle, anannular tlofw chamber, and at least one spiral channelat Vthe Vperiphery of said bore'connectsaid oneend thereof, the inner end of said orilce being adjacent the longitudinal axis of saidbore and the axis of said orice extending at an angle to the longitudinal .axis of said bore andvat approximately a'right angle to the surface of VSaid lendvvall at the inner end of said or'ice, and said coremeans'having a central tip yportion extending into saidiirst-named chamber beyond the discharge end of said spiral channel, the surface of which tip `portionconverges at the longitudinal axis of the :bore at ,anacute angle thereto, theiangle of convergence being .greater than the angle of convergence between Ythe axis ,and the end wall of -said bore, whereby'the surface of said tip portion and the end wall of said bore vin said iirst-named chamber diverge 'from eachl other toward theapex of lsaid chamber. f

16. A spray tip for .a fuel injection nozzle or the like comprising .a shell vhaving a bore vterminating near .one end thereofand core ymeans in said'shell extendinginto spaced relation with the inner end of rsaid bore, said `shell and core kforming a-chamber at` thek inner end 4 o'isaid bore,

f the end -wall of the Ybore forming'said chamber converging toward the longitudinal axis ofthe bore at an acute angle, an annular ow chamber, and atleast onespiral channel `at the periphery vvof Vsaid bore connecting said chambers, said shellhaving an `outlet orifice in said one end thereof, the `inner-end of said orifice being adjacent the ,longi- `tudinal axisof said bore andthe axis-of said orifice exf tending at an angle to the longitudinal axis of saidbore and at approximately a right angle to the surfaceof said end wall at theinner end of said orifice, -andsaidcore means having :a central :tip yportion .extending Yinto said 5 mst-named chamber beyond the discharge end of said spiral channel, the surface of which tip portion converges at the longitudinal axis of the bore at an acute angle thereto.

References Cited in the file of this patent UNITED STATES PATENTS 1,810,689 Townsend et al. June 16, 1931 6 Broeze Feb. 15, 1938 Gold et a1. Sept. 3, 1940 FOREIGN PATENTS Sweden June 20, 1933 France Mar. 10, 1928 Germany Apr. 13, 1953 France Apr. 25, 1951 

